'We are united in opposing the death penalty in this case as we are in every case,' she said.

'We would plead with the Indonesian government and the people of Indonesia ... for the lives of two young men who have made enormous transformations in their lives and who are making enormous transformations in the lives of other people as well.'

In the Senate, Attorney-General George Brandis said the government had made at least 22 representations to Indonesian officials since January in a bid to save the two men.

That included letters and phone calls from Prime Minister Tony Abbott, Ms Bishop and the Australian Federal Police.

ASIO chief Duncan Lewis and Attorney-General Department secretary Chris Moraitis had also been sent to Indonesia to plead for the pair.

Foreign Minister Julie Bishop has used parliament to directly plead with the Indonesian president to spare the lives of two Australian drug smugglers

Indonesia's ambassador Nadjib Riphat Kesoema has written to federal parliament defending his government's decision not to save two Australian drug smugglers on death row.

The Senate last month urged the Indonesian government to spare the lives of Bali Nine duo Andrew Chan and Myuran Sukumaran, who are expected to face the firing squad in the next few days.

In response, Mr Kesoema said the decision not to pardon the pair was very difficult for President Joko Widodo on both a personal and humanitarian level.

However, the drug problem had 'blossomed into a national emergency' and required strong law enforcement.

'Most tragically, drugs and their traffickers and producers have denied too many people including children of their right to life,' he wrote.

Mr Kesoema said both cases had been granted due process of law and all legal avenues had been pursued.

He defended the court's decision to impose the death penalty and said separation of powers meant the government could not meddle in judicial processes.

The upper house had argued the sentences should be commuted to a prison term due to the pair's genuine remorse and rehabilitation.

Chan and Sukumaran were transferred to Nusakambangan island on Wednesday to await their execution.